Conductor for train-control systems



June 1927' T. E. CLARK CONDUCTOR FOR TRAIN CONTROL SYSTEMS 3 Sheets-Sheet 1 Filed April 14, 1924 INVENTOR. Thomas E C/a By ATTORNEY."

June 7, 1927. 1,631,361

T. E. CLARK v CONDUCTOR FOR TRAIN CONTROL SYSTEMS Filed April 14. 1924 3' sham-sheet 2' I. I 4 03: I I. V j 50 47- 50 4'6 INVENTOR. 7770/7705 E C/ark A TTORNEY.

June 7, 1927.

' 1,631,361 'r. E. CLARK CONDUCTOR FOR TRAIN CONTROL SYSTEMS Fil'e'd April 14, 1924 a Sheets-Sheet'ZS 1 2 72' 73 43 J ll 4:5" 5: I n 4 a I 73 7 44 $0 452v 9;! {a 44 V I g a: I H 4 HI v u 73 72 73 I a: 9 J26 INVENTOR. Thomas /7// A TTORNE Y.

Patented June 7, 1927.

Law

EFEWQJEM,

THOMAS CLARK, or nnrnorn'mieriiean, nssrenon 'ro eonrinuous rnalniicon- TROL CORPORATION, or DETROIT, MICHIGAN, aCORPORATIONeriviIeirIeAm CONDUCTOR r03 rnmn oon'rnon SYSTEMS.

Applicationfiled April 14, 1924. Serial N0= '706,3 75.

This invention relates to the control of railway trains by means of radio-frequency currents carried by the rails in the manner and those in which the track rails rest on steel viaducts or bridges.

When the properly equipped vehicle passesover or comes to rest in a dead section, no-proper signal can be received from the rails, even it the track ahead is clear.

My invention consists in a proper connection between the blocks on-each side or such'dead section so that the train controlling Current may be the sameon both sides of such dead sectionand be present in proper auxiliary conductors throughout such dead fs-ections so that the locomotive or other controlled vehicle passing through orremaining over said section may receive proper train c'ontrollingimpulses. I

This invention may be embodied in railway tracks having such dead sections "in'the manner illustrated conventionally in the accompanying drawings, in which Fig. 1 is a diagrammatic, planof a. railway crossing wherein the tracks areprovided-.withmy novel conductors. Figs; 2- to 8 inclusive are siniilar-views' of modified embodiments of this invention.

Similar reference characters refer to'like 'or carrier currents 'upon the outer rai'ls 15 parts throughout the several views.

In the train control system shown in any said pending application, a transformer is provided for supplying radio-frequency current, also called carrier current, to each block, and where the track is used for one this, transformers connected to way tratti'c, the departure end of the blocln The rails are also used as the conductors jof'the usual current to operate or control the signal system and either this, current orthe carrier current energizes a relay at the entrance end I of the block ti'onthetransftuineroi the next block insuch arrangements.

and 15 and 16 on the other.

- in" Fig. 1}, but

which relay controls the operanecessary to carry the rear. It a lbloclc is occupied, the rails thereof are short-circuited. and the relay con trolling the next block in the rear is de- "energized' and .dahgerconditions are set up in thetr'anstormer of the next block in the rear. Danger conditions inany block result in caution conditions in .the next block thereto, toward the rear; 1

Where thetracks rest directly on the steel work of bridges or viaducts, or' whereraiL way crossings occur, the rails canliot'be used as conductors of thesignal and: carriercurrents so other niea ns must be provided to carry these currents around such sections.

The several figures of the drawings show Inl ig. 1, I have'shown tworailwaytracks crossing each other, the crossing itself comprising the rails 1 to 1-2 inclusive; The rails 7 and 8' are in alinement withbut insulated from the rails 13a1id: '14 respectively, while the rails 1'1 and 12 are inalinement with but insulated from the rails 15 and 16 respectively; The crossing:comprising the rails 1 to 12 inclusive 1s a dead'section'and the ordinary signal currents are usually conducted around such sections by means of Wires 1 and 18 shown in dotted l-inesyconnecting to the adjacent rails- 13" and 14 on one side The ordinary track battery1-9 connects to rails15 and 16 in the usual manner. The instrumentalities are indicated as a unit; by the' letter B form no -pa rt of-Ethe present invent-ion. I I As described in my said application, means Aare provided toimpress radio-frequency and '16. 1 While any-desired means may be us'cdtor this purpose, I have conventionally indicated a: generator 21, a transformer 22,

"a standard high-frequency generating tube 23, variable indu'ct'an'ce 24, resistance 25,, battery. 26, condensers 27 and wires ZSi-and 29"connecting to the rails 15 and'16respective'ly'; J v I I Conductors 32and 33- are shown extends ing from the rails 15 and 16 to the rails '13 and 14; respectively; These conductors will usually be made --much 116317181" than v the 'si and carrier signaling and control purposes and as trains enter this track from the left in Fig. 1, a

I strong induced field travels ahead of the first axle of the train and proper instrumentalities on the train respond thereto.

The wires 17 and 18 could be used to conduct the carrier currents and when presentmay carry them, but I prefer to install the heavy wires 32 and '33 even when wires 17 and '18 are present. The signal currents and the carrier currents do not affect each other. The wires 17 and 18 are usually carried by poles atcross-overs a distance from the rails and under those conditions would not be practical as conductors ,of carrier currents which should be carried by conductors placed as near as possible to the rails so that the magnetic flux of the carrier currents will properly affect the collecting instrumentalities onthe locomotives at the cross-over points.

My experience has been that the highfrequency' generators operate properly in circuit with the track batteries and track relays, the reason probably being that the internal resistances of the batteries and relays are many times that of the rails and conductors 32 and 33. I have found little difference in the carrier currents in the rails whether the batteries and relays were connected or not. Some carrier current probably flows through both track batteries and rerlays but the amount is of no consequence.

In my former application, I have choke coils to prevent this flow but subsequent tests have shown that they'may be omitted.

i In the structures shown in Figs. 2 to 8 inclusive, the rails 41 and 42 of the dead sections are insulated electrically from the rails 43 and 44 on the entrance side'and the rails 45 and 46 on the departure side. In each case transforming and transmitting instrumentalities A connect to the rails 45 and 46 respectively by means of the wires '47 and 48.

In Fig. 2, the rails 43 and 44 are again connected by a balancing condenser 49 but .a condense 50 is shown in each of the conductors 51 and 52 connecting the rails 45 and 46 to the rails 43 and 44 respectively.

In this construction the wires 53 and 54 to carry the signal currents areretained as these currents cannot pass the condensers 50. But as a portion of the carrier current can also .pass' over these wires, when conditions are favorable, it may be found desirable to insert the inductances or choke coils 55 in these conductors, as shown 1n. Figs. 3 to 8 lnclusive, to stop the radio-frequency current while permitting the track signal curv rents to pass. The balancing condenser may be omitted, if desired, but such a condenser is usually tound desirable at the entrance end of each block to complete the circuit for the carrier current.

In Fig. 4, the wires 53 and 54 with their inductances 55 are the same as. above described but the conductors 56 and 57 are provided with condensers 50 at each end. In certain exposed sections, such as tracks laid on metal bridges, there is danger of the conductors 53 and 54 becoming disturbed and grounded. Under such conditions the track signal circuit would also be grounded, but the passage of the track signal current over the conductors 53 and 54 to the pointwhere the grounding occurs will be prevented by these condensers 50.

' In Fig. 5, the conductors 58 and 59 c0nnect to the rails 45 and 46 through condensers 50. At the opposite end of the dead section, the rails 43 and 44 are connected by means of an adjustable inductance 60 and two condensers 50. The ends of the conductors 58 and 59 have sliding contact with this inductance to vary the amount of inductance between the conductors and the ad jacent rails or track sections. The reason for this is that the length of the track sections, indicated by 43 and 44 in this figure, may vary greatly and with variation in length will be a variation in capacity. By making use of the variable and adjustable inductance the capacity is compensated for. The inductance has the effect of building up a current condition at the departureend of the block indicated by 43 and 44, and by varying this inductance the character of the,

carrier current for this block can be accurately adjusted to compensate for the variations in capacity of theblock.

In Fig. 6 a loose coupled inductance consisting of the primary winding 61 connected to the conductors 62 and 63 and the secondary winding 64 connecting to the rails 43 and 44 through the condensers 50 is used for this same purpose of compensating forthevariations in capacity of the block indicated by 43 and 44.

In. Fig. 7, a loose coupled inductance connects the rails 45 and 46 to the conductors 66 and 67 and another such inductance connects these conductors to the rails 43 and 44. Each inductance consists of. a primary winding 61 and a secondary winding .64. The closed oscillating circuit consisting of the rails 45 and 46, the winding 61 and condenser 50, the wires 47 and 48 and the twins former A, produce an induced current in) the adjacent secondary winding 64 and therefore 'in the closed oscillating circuit consisting of the conductor-s66 and 67 and; in'the primarytil at the-'opposite'en'd ot the conductors; This induced current produces a second inducedcurrent in the third closed.

'ductor,.- and means-to electric-all connect the opposite ends: of said conductonszto said rails oscillating circuit-consisting of the adjacent secondary winding 64:, condenser 50 and traclrrailsA?) and 44:. which are again con-.

nected at their entrance end by a balancing condenser of the usual type. I

In Fig. 8, a complete oscillating circuit oi the full length of the block is provided. The

circuit consists of two long sides, the transmitting mechanism A and the well known balancing condenser at the entrance end of the block. The sides of the circuit bridge a dead section by means of the conductors 70 and 71 which connect to the rails at the ends of the dead section by means of the condensers 50 and adjustable inductances, each comprising a primary winding 72 and a secondary winding 73. In such a construction, the carrier current is more liable to be uniform throughout the length of the block.

,These examples of constructions for bypassing dead sections with train control currents such as is required in the system described in my co-pending application indicate that other modifications are possible and may be made by those skilledin the art Without departing from the spirit of invention as set forth in the following claims.

I claim 1. In a train control system, in combination \vlth a two-rall track divlded into blocks nisulated from each other, means to impress radio-frequency current on one of the blocks, conductors electrically connecting the rails of said block to the-rails of a second nonadjacent block in. the direction from from which trains approach, and a condenser between the rails of Said second block.

2. In a train control system, in combination with a two-rail track divided into blocks insulated from each other, one of said blocks constituting a dead section, means to impressradio-frequency current on the rails or one of the blocks, conductors electrically connecting the rails of said last named block to those of another block on the opposite Side of said dead section, and means embodying a condenser connecting the rails of said last named block.

3. In a train control system, a pair of rails, means to impress radio-frequency current on said rails, a pair of conductors ex tending parallel to the rails and having ends connected to the rails adjacent the current supply, a balancing condenser in each conductor, and means to electrically connect the opposite ends of said conductors to said rails at a distance from the point of attachment of said current supply.

4.,In a train control system, rails, means to impress radiofrequency curblocks at oneside of said dead'section,

a pair of renton-said; rails, aeipair ofi'conductors exat :a dist aiicefromthe point ot attachment of said current supply comprising a varia blc coupler of which the'primary coil con nects to the conductors and the secondary coil connects to the rails.

5. In a train control system, a pair of rails, means to impress radio-frequency current on said rails, a pair of conductors extending parallel to the rails and haying ends connected to the rails adjacent, the current supply, a balancing condenser in each conduct-or, means to electrically connectthe opposite ends of'said conductors to said rails at a distance from the point of attachment of said current supply comprising a variable coupler of which the primary winding connects to both conductors, and a pair of condensers connecting the ends of the secondary winding of the coupler to the rails.

6. In a train control system, a two-rail track divided into blocks insulated from each other, one of said blocks constituting a dead .section, means to impress radio-frequency current on the rails of one of the blocks at one side of said dead section, and

' receiving said currentand to the rails of a block on the other sideof said dead section, said last named connection comprising a variable inductance. F

7. Ina train control system, a two-rail track divided into blocks insulated from each other, one of said blocks constituting a dead section, means to impress radio-frequency current on the rails of one 01. the and conductors electrically connected to the rails receiving said current and to the rails of a block on the other side of said dead section, said last named connection comprising a variable inductance and a pair. of condensers.

8. In a train track divided into blocks insulated from each other, one of said blocks constituting a dead section, means to impress radio-frequency current on the rails of one of the blocks at one side of said dead section, conductors electrically connected to the rails receiving said current and to the rails of a block on the other side of said dead section, said last named connection comprising a variable inductance and a pair of condensers, and conductors for signaling current extending around said dead section and connecting to the rails v v 9. In a train control system, a two-rail track divided into. blocks insulated from each control system, a two-rail Cal parallel to the rails of said dead section to and electrically connected to the rails on the opposite side of said dead section and a con- 10 denser in each of said conductors to prev cut the passage of direct currents.

THOMAS E. CLARK. 

